Wave making device

ABSTRACT

The wave making device comprises a caisson connected to an air blower and to a control valve mechanism comprising an exhaust valve adapted to move between a closed position and an open position, and a system adapted to move the exhaust valve and to maintain said exhaust valve into said position. The control valve mechanism is adapted to ensure continuously an air pressure within the caisson at least equal to the atmospheric pressure.

FIELD OF THE INVENTION

The present invention relates to an artificial wave making device, andto a process for making artificial wave at the surface of a pool.

BACKGROUND OF THE INVENTION

Artificial wave making devices are commercialized by the company “WOWCompany”. Said devices comprises a floating spherical element in which asystem moves at least one body so as generate downwards and/or upwardsmovement of the floating spherical element, whereby generatingartificial wave at the surface of the pool.

Artificial wave making devices have also been developed by using a highflow and high pressure air-blower to blow or draw air periodically in agiven frequency to form waves. If the area of a pool is about 700 m², anair-blower having output power of 165 kW is required. Said devices havehigh energy consumption and require great investment, so it is notsuitable for aquatic breeding.

U.S. Pat. No. 4,730,355 to Mark L, Kreinbihl et al. discloses anartificial wavemaking device comprising a motor, an air-blower, afour-way air directional valve assembly, pipes and wave chambers.However, the wave generated by said device is still based on the methodof forced vibration. Therefore, said device has to be provided with anair-blow of great output power, and the cost of the device is stillhigh.

U.S. Pat. No. 5,226,747 to Wang Yichang et al. discloses a wave makingdevice using the principle of liquid resonance of the shock wave and thewave in the water pool to provide an artificial wave making method andapparatus based on adaptive resonance so as to lower the energyconsumption for generating the artificial wave, and particularly, toonly a few hundredths of that for generating waves by forced vibration.

The wave making device of Wang et al comprises:

-   -   an air chamber,    -   four butterfly valves,    -   air pipes and    -   an adaptive control system which comprises a float disposed on        the water surface, a sensor, a control circuit, a first and a        second electromagnetic actuators and a polarity switch of the        sensor, said float being disposed at a distance from the air        chamber.

The control circuit of Wang et al comprises a signal amplifier, ashaper, a first and a second power amplifiers, a phase inverter and anoscillator, said oscillator being switched on when starting to generatea certain exciting frequency transferred to the control circuit untilthe water wave excites feedback signals, and said oscillator being cutoff once the device is started, and said sensor receiving the signals ofthe water wave from the float, and translating them to the signalamplifier and the shaper via the polarity switch of the sensor, theamplified and shaped signals being further transferred to the firstpower amplifier, and to the second power amplifier via a phase inversor,said first and second power amplifiers respectively actuating the firstand the second actuators to control said four butterfly valves to openor close according to the rhythm of the water wave to form a shock wavein resonance with the water wave, said first and second valves beingprovided in the pipe at the discharge side of the air blower, and thethird and the fourth valves being provided at the inlet side of the airblower, and said first and fourth valves being respectively communicatedwith the atmosphere, and said second and third valves being respectivelycommunicated with the air chamber, therefore, the four valves formingthe following four operation modes based on the rhythm of the water waveand according to the moving direction of the float being from higherportion to lower position or in reverse, and the position of thepolarity switch of the sensor:

No of the Moving Polarity Actuator direction switch of being State ofvalves Mode of the floot the senser operated No. 5 6 7 8 1 High→Low + 31 0 1 0 2 Low→High + 4 0 1 0 1 3 High→Low − 4 0 1 0 1 4 Low→High − 3 1 01 0 wherein: “1” means open; “0” means closed.

In the device of Wang et al, the blower is once used for blowing airinto the chamber, and once used for drawing air outside the chamber.

In order to use one single blower, various valves are required.

The use of such a large number of valves increases the risk ofmechanical problems, as well as the problem of correct control of thetiming of the closing or opening of the valves, whereby causingvariation which are detrimental for achieving the desired wave pattern.

Furthermore, as the blower is intended to suck periodically air from thechamber, so that liquid flows into the chamber, a risk exists that wateror water droplets are sucked into the blower, causing then problems ofcorrosion, growth of bacteria, etc.

The invention relates to artificial wave making device simple ofconception, with a low energy consumption and using a caisson containingair with always an air pressure at least equal to the atmosphericpressure, i.e. at least a low over pressure with respect to the ambientatmospheric pressure.

BRIEF DESCRIPTION OF THE INVENTION

The invention relates to an adaptive control artificial wave makingdevice for generating wave with at least one specific wave pattern, atleast at the surface of a liquid contained into a pool located in an aircontaining atmosphere having an ambient pressure, said surface of theliquid having an average liquid level. The pool is advantageously aswimming pool, but can also be an aquarium or a treatment pool, forexample for treating waste liquid, liquids to be aerated, liquids to bemixed with floating foam, for displacing floating foam or materialtowards a receiving means, receptacle, etc.

The wave making device comprises at least:

-   -   a caisson adapted to be mounted at least partly into a pool        containing a liquid, said caisson having at least an upper        portion and a bottom portion intended to be immersed in the        liquid of the pool below the average liquid level in the pool.

At least a part of the upper portion of the caisson is adapted tocontain air when the bottom portion of the caisson is immersed into theliquid of the pool. Said caisson has a face, advantageously a bottomprovided with an opening adapted, when the caisson is partly immersedinto the liquid of the pool, to form a passage of liquid from the pooltowards the caisson, and inversely. Liquid can thus flow in the caissonand out of the caisson. The caisson can possibly be divided in one ormore distinct chamber with each one or more openings for the passage ofliquid.

-   -   an air blower adapted to create an outlet air flow with an over        pressure comprised between 0.01 10⁵ Pa and 0.5 10⁵ Pa above the        atmospheric pressure, advantageously an over pressure comprised        between 0.05 10⁵ Pa and 0.3 10⁵ Pa above the atmospheric        pressure.    -   an air pipe connecting the air blower to the upper portion of        the caisson, so as to introduce air into the upper portion of        the caisson whereby generating in said upper portion of the        caisson an air pressure at least equal to the atmospheric        pressure, advantageously an over pressure comprised between        0.005 10⁵ Pa and 0.5 10⁵ Pa above the atmospheric pressure,        advantageously an over pressure comprised between 0.01 10⁵ Pa        and 0.3 10⁵ Pa above the atmospheric pressure.    -   at least one control valve mechanism connected to the upper        portion of the caisson. Said control valve mechanism comprises        an exhaust valve adapted to move between at least a        substantially closed position and a substantially full open        position, and a system adapted to move the exhaust valve and to        maintain said exhaust valve into one position selected from the        group consisting of the substantially closed position, the        substantially full open position and partly open positions        comprised between the substantially closed position and the        substantially full open position, whereby said control valve        mechanism is adapted to ensure continuously air pressure within        the caisson at least equal to the ambient pressure,        advantageously at an over pressure with respect to the ambient        pressure, preferably an over pressure comprised between 0.01 10⁵        Pa and 0.3 10⁵ Pa above the atmospheric pressure. According to a        preferred embodiment the exhaust valve is moving between a fully        closed position and a fully open position.    -   a pressure sensor for determining a liquid pressure or a        difference of pressure at a liquid level of the caisson or        vertically below the bottom opening of the caisson,        advantageously a submersible pressure sensor placed in the        bottom portion of the caisson or below the bottom opening of the        bottom portion of the caisson, at a determined level with        respect to the bottom of the caisson, whereby at said determined        level, liquid is always present when the caisson is placed in        the pool for generating wave, the said submersible sensor        measuring a difference of pressure of the liquid at the        determined level into the caisson with respect to the ambient        pressure and generating advantageously an electrical signal        function of the measured difference of pressure, such as a        signal of less than 100 mA, advantageously of less than 50 mA, a        signal of less than 50V, for example comprised between −20V and        +20V. the signal can also directly be a digital signal. The        sensor can also be not immersed, when for example using a tube        open at its bottom end and connected at its upper portion to the        pressure sensor.    -   possibly a converter for converting the electrical signal of the        pressure sensor, advantageously the submersible pressure sensor        into a converted signal; and    -   a controlled command system receiving a signal selected from the        electrical signal of the submersible pressure sensor and the        converted signal, said controlled command system determining the        moments when the exhaust valve has to be moved into a position        selected from the group consisting of the substantially full        open position and partly open positions comprised between the        substantially closed position and the substantially full open        position, and/or the moments when the exhaust valve has to be        moved into its substantially closed position, for achieving said        specific wave pattern, and emits a signal towards the control        valve mechanism for commanding the movement of the exhaust valve        or valves for achieving said specific wave pattern.

According to an embodiment, the system adapted to move the exhaust valveand to maintain said exhaust valve into one position selected from thegroup consisting of the substantially closed position, the substantiallyfull open position and partly open positions comprised between thesubstantially closed position and the substantially full open positioncomprises at least one cylinder. Said cylinder acts advantageouslyagainst the action of a return mechanism, said return mechanism beingadvantageously adapted for directing the valve towards its substantiallyclosed position. Other systems for controlling the movement of theexhaust valve than one or more cylinders are possible. For example, themovement of the valve can be operated by a motor moving one elementconnected to the valve, for example a linear motor, etc.

According to an advantageous detail, the caisson is provided with anexhaust pipe for the exhaust of air from the caisson, whereby thecylinder is located within the exhaust pipe.

According to another detail of an embodiment, the ratio open surface ofthe exhaust valves or valves expressed in cm²/volume of the upperportion of the caisson is greater than 0.0005, advantageously greaterthan 0.001, preferably comprised between 0.005 and 0.05. With such aratio, it is possible to ensure a rapid exhaust of air from the caisson.

According to a further detail of an advantageous embodiment, the controlvalve mechanism comprises a pipe connecting the valve with the caisson,said pipe being provided at its end connected to the caisson, with aliquid blocking system adapted to prevent the passage of liquid and gastowards the valve, when the liquid level in the caisson is above apredetermined level. This is advantageous for ensuring a minimum airvolume within the caisson.

According to a further detail of an advantageous embodiment, the bottomof the caisson is open, said bottom being provided with a series ofelements defining passages with a maximum width or diameter of less than10 cm. The bottom is for example provided with a open grid forpreventing the passage of large object into the caisson.

According to an embodiment, the blower is adapted to blow a volume ofair of at least 30 litres per second (for example comprised between 100litres and 500 litres per second) per 200 litres of the upper portion ofthe caisson.

According to an advantageous detail, the bottom of the caisson has anopening having an open surface corresponding to 3% to 10%,advantageously 4% to 7% of the surface of the liquid of the pool. Thisvalue is for a tank or caisson with small losses of energy. If the tankor caisson has bigger losses, the ratio has to be higher, for examplebetween 10 to 20%.

If the pool is located in a room, in a closed or substantially closedroom, the device comprises then advantageously an exhaust pipe forexhausting air from the caisson outside the said room.

The controlled command system comprises preferably instructions formaintaining the exhaust valve or valves of the caisson in itssubstantially closed position for a time sufficient so that a sufficientamount of air from the blower is introduced into the caisson, so thatpart of said air is exhausted into the pool through the bottom opening.This is advantageous for expelling out of the caisson or out of thegrid, possible materials or components floating within the caisson orblocking partly the grid.

Preferably, the instructions for maintaining the exhaust valve or valvesof the caisson in its substantially closed position for a timesufficient so that a sufficient amount of air from the blower isintroduced into the caisson are adapted for exhausting air into the poolfor at least 1 second to 10 minutes, preferably 5 second to 1 minute,per period of at least 45 minutes, advantageously per period comprisedbetween 1 hour and 24 hours.

This is advantageous for controlling the good working of the blower andof the exhaust valve(s) from time to time.

According to a specific embodiment, the caisson has a lateral wall incontact with the liquid of the pool outside the caisson, the said wallhaving an opening with a portion at least located below the averageliquid level and an opening with a portion located above the averageliquid level of the pool, or having at least a first opening locatedabove the average liquid level of the pool and a second opening locatedbelow the average liquid level, and in which the said opening oropenings are provided with movable closing means, whereby enabling thepassage of water from the pool into the caisson when the opening oropenings are not closed by the movable closing means.

According to a further specific embodiment, the device further comprisesat least one filtering means or a treatment unit for filtering ortreating air flowing into the blower and/or pushed by the blower. Theair exhausted can also be treated if required.

The adaptive control artificial wave making device of the invention canalso comprise two or more distinct caissons connected to a same airblower, or to different blowers, through a piping system provided with avalving system for controlling the flow of air towards the first caissonand the flow of air towards the second caisson, whereby each caisson hasat least one control valve mechanism connected to the upper portion ofthe caisson. Said control valve mechanism comprises:

-   -   an exhaust valve adapted to move between at least a        substantially closed position and a substantially full open        position, and    -   a system adapted to move the exhaust valve and to maintain said        exhaust valve into one position selected from the group        consisting of the substantially closed position, the        substantially full open position and partly open positions        comprised between the substantially closed position, the        substantially frill open position.

The invention also relates to the use of the adaptive control artificialwave making device of the invention for generating artificial wave atthe surface of a pool, which could be located in a room. The air fromthe caisson is advantageously exhausted outside the room or towards atreatment station.

The invention relates also to a method for generating artificial wave atthe surface of a liquid contained in a pool located in a room, in whichan adaptive control artificial wave making device of the invention isused, in which the air from the caisson is exhausted outside the room ortowards a treatment station, said method comprising at least thefollowing steps:

-   -   creating by means of the air blower of an outlet air flow with        an air pressure at least equal to the atmospheric pressure        towards at least one caisson having its bottom portion immersed        into the liquid, whereby generating in the upper portion of the        caisson an air pressure at least equal to the atmospheric        pressure;    -   controlling by the working of at least one exhaust valve        associated to the upper portion of the caisson between at least        a substantially closed position and a substantially full open        position, by the system adapted to move said at least one        exhaust valve and to maintain said at least one exhaust valve        into one position selected from the group consisting of the        substantially closed position, the substantially frill open        position and partly open positions comprised between the        substantially closed position, the substantially frill open        position, whereby said control valve mechanism is adapted to        ensure continuously air pressure within the caisson at least        equal to the ambient pressure, whereby the pressure within the        caisson varies so as to generate a liquid flow between the        caisson and the pool;    -   determining a parameter selected from the group consisting of        liquid pressure, a difference of pressure at a liquid level of        the caisson, a difference of pressure vertically below the        opening of the caisson, by at least one submersible pressure        sensor placed at a determined level for determining, whereby at        said determined level, liquid is always present, the said        submersible pressure sensor measuring a difference of pressure        of the liquid at the determined level into the caisson with        respect to the ambient pressure and generating an electrical        signal,    -   transmitting the electrical signal to a controlled command        system for (a) determining moments selected from the group        consisting of the moments when at least one exhaust valve has to        be moved into a position selected from the group consisting of        the substantially full open position and partly open positions        comprised between the substantially closed position, the moments        when at least one exhaust valve has to be moved into its        substantially closed position, for achieving said specific wave        pattern, and (b) emitting a signal towards the control valve        mechanism for commanding the movement of the exhaust valve for        achieving said specific wave pattern at least at the surface of        the liquid contained into the pool.

The invention further relates to a method for generating artificial waveat the surface of a liquid contained in a pool located in a room, inwhich an adaptive control artificial wave making device of the inventionis used, in which the air from the caisson is exhausted outside the roomor towards a treatment station, said method comprising at least thefollowing steps:

-   -   creating by means of the air blower of an outlet air flow with        an air pressure at least equal to the atmospheric pressure        towards at least one caisson having its bottom portion immersed        into the liquid, whereby generating in the upper portion of the        caisson an air pressure at least equal to the atmospheric        pressure;    -   controlling by the working of at least one exhaust valve        associated to the upper portion of the caisson between at least        a substantially closed position and a substantially full open        position, by the system adapted to move said at least one        exhaust valve and to maintain said at least one exhaust valve        into one position selected from the group consisting of the        substantially closed position, the substantially fall open        position and partly open positions comprised between the        substantially closed position, the substantially full open        position, whereby said control valve mechanism is adapted to        ensure continuously air pressure within the caisson at least        equal to the ambient pressure, whereby the pressure within the        caisson varies so as to generate a liquid flow between the        caisson and the pool;    -   determining a parameter selected from the group consisting of        liquid pressure, a difference of pressure at a liquid level of        the caisson, a difference of pressure vertically below the        opening of the caisson, by at least one submersible pressure        sensor placed at a determined level for determining, whereby at        said determined level, liquid is always present, the said        submersible pressure sensor measuring a difference of pressure        of the liquid at the determined level into the caisson with        respect to the ambient pressure and generating an electrical        signal,    -   converting the electrical signal by a converter into a converted        signal,    -   transmitting the converted signal to a controlled command system        for (a) determining moments selected from the group consisting        of the moments when at least one exhaust valve has to be moved        into a position selected from the group consisting of the        substantially full open position and partly open positions        comprised between the substantially closed position, the moments        when at least one exhaust valve has to be moved into its        substantially closed position, for achieving said specific wave        pattern, and (b) emitting a signal towards the control valve        mechanism for commanding the movement of the exhaust valve for        achieving said specific wave pattern at least at the surface of        the liquid contained into the pool.

Details and particulars of the present invention will become apparentwith the following description of the presently preferred embodiments,given as example only.

BRIEF DESCRIPTION OF THE DRAWINGS

In said figures:

FIG. 1 is a schematic view of a pool provided with a device according tothe invention;

FIG. 2 is a perspective view of the caisson;

FIGS. 3A and 3B are cross section views of the exhaust valve of thecaisson, in open and closed position;

FIGS. 4A and 4B are cross section views of an embodiment of exhaustvalve provided with a liquid-air blocking means in open and blockedpositions;

FIGS. 5A, 5B and 5C are views of the pool of FIG. 1, in different airlevel within the caisson;

FIG. 6 is a schematic view of a pool provided with two distinctcaissons.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a schematic view of an adaptive control artificial wave makingdevice 1 for generating wave W with at least one specific wave pattern,at least at the surface LS of a liquid L contained into a pool P locatedin a room R with an air containing atmosphere having an ambientpressure. The surface LS of the liquid has an average liquid level ALS.The pool P is for example a swimming pool, a treatment basin, anaeration/oxygenation treatment pool, an aquarium, etc. The wave heightgenerated by the device is advantageously lower than 100 cm, preferablylower than 50 cm, said height being the difference between the maximumlevel achieved by the wave and the average liquid level in the pool.

The wave making device 1 comprises at least:

-   -   a caisson 2 adapted to be mounted at least partly into the pool        P containing the liquid L possibly with some foam. The caisson 2        having at least an upper portion 3 located above the average        liquid level ALS and a bottom portion 4 intended to be immersed        in the liquid of the pool below the average liquid level ALS in        the pool.

At least a part of the upper portion 3 of the caisson 2 is adapted tocontain air (possibly mixed with one or more other gases, such asoxygen, so as to form oxygen enriched air) when the bottom portion 4 ofthe caisson is immersed into the liquid of the pool. Said caisson has abottom 5 provided with an opening adapted, when the caisson 2 is partlyimmersed into the liquid L of the pool, to form a passage of liquid fromthe pool towards the caisson, and inversely (arrows LF). Liquid can thusflow in the caisson and out of the caisson. The caisson can possibly bedivided in one or more distinct chamber with each one or more openingsfor the passage of liquid. The bottom 5 of the caisson 2 can be directedtowards the bottom BP of the pool P, or to any other direction betweenthe vertical and the horizontal, as long as it is always fully immersed.

-   -   an air blower 6 adapted to create an outlet air flow AF with an        over pressure comprised between 0.01 10⁵ Pa and 0.5 10⁵ Pa above        the atmospheric pressure, advantageously an over pressure        comprised between 0.05 10⁵ Pa and 0.3 10⁵ Pa above the        atmospheric pressure. The air is advantageously sucked from the        outside of the room R, and is for example filtered (filter 7)        before entering into the blower 6.    -   an air pipe 8 connecting the air blower 6 to the upper portion 3        of the caisson 2, so as to introduce air into the upper portion        of the caisson whereby generating in said upper portion of the        caisson an air pressure at least equal to the atmospheric        pressure, advantageously an over pressure comprised between        0.005 10⁵ Pa and 0.5 10⁵ Pa above the atmospheric pressure,        advantageously an over pressure comprised between 0.01 10⁵ Pa        and 0.3 10⁵ Pa above the atmospheric pressure.    -   at least one control valve mechanism 9 connected to the upper        portion 3 of the caisson 2. Said control valve mechanism 9        comprises an exhaust valve 10 adapted to move between a closed        position (FIG. 3B) and a full open position (FIG. 3A), and a        cylinder 11 adapted to move the exhaust valve 10 and to maintain        said exhaust valve into the open position against the action of        a return spring 12, while the spring 12 maintains the closed        position, as soon as the cylinder is no more working. The        control valve mechanism 9 is adapted to ensure continuously air        pressure within the caisson 2 at least equal to the ambient        pressure, advantageously at an over pressure with respect to the        ambient pressure, preferably an over pressure comprised between        0.02 10⁵ Pa and 0.3 10⁵ Pa above the atmospheric pressure.    -   a submersible pressure sensor 13 placed below the bottom opening        5 of the bottom portion 4 of the caisson, at a determined level        with respect to the bottom of the caisson, whereby at said        determined level, liquid is always present when the caisson is        placed in the pool for generating wave, the said submersible        sensor measuring a difference of pressure of the liquid at the        determined level into the caisson with respect to the ambient        pressure and generating an electrical signal function of the        measured difference of pressure of less than 100 mA,        advantageously of less than 50 mA. According to a more        advantageous embodiment, the sensor 13 is placed within the        caisson 2 adjacent to the bottom opening, instead of being        placed at the bottom of the pool, vertically below the opening 5        of the caisson 2. It can also be placed on the side of the        caisson.    -   optionally a converter for converting the electrical signal of        the submersible pressure sensor into a converted signal.    -   a controlled command system 14 receiving a signal selected from        the electrical signal of the submersible pressure sensor and the        converted signal, said controlled command system determining the        moments when the exhaust valve has to be moved into a position        selected from the group consisting of the substantially full        open position and partly open positions comprised between the        substantially closed position, and/or the moments when the        exhaust valve has to be moved into its substantially closed        position, for achieving said specific wave pattern, and emits a        signal towards the control valve mechanism for commanding the        movement of the exhaust valve for achieving said specific wave        pattern.

The cylinder 11 is located within the exhaust pipe 15 conducting airtowards the outside of the room R.

The valve 10 is adapted to contact the upper surface of a tube 16 fixedon the wall of the caisson 2. This enables to prevent water to flow intothe pipe 15 and to collect possible water condensing into the pipe andevacuating said water outside the pipe 15 by an opening 17 of the pipe.

The ratio open surface 18 of the exhaust valve 10 expressed incm²/volume of the upper portion of the caisson is comprised between0.005 and 0.05. With such a ratio, it is possible to ensure a rapidexhaust of air from the caisson, when the valve is in open position.

The position of the cylinder 11 within the pipe 15 is maintained bymeans of arms 19.

For preventing the passage of dust or objects from the caisson towardsthe pipe 15, the tube can be provided with a gas filter element 20.

The tube 16 or the opening 21 of the caisson 2 can be provided with apiping system 22 (shown in dashed lines in FIG. 3A) for preventing thepassage of dust or solid floating material. The piping system 22comprises a vertical tube 23 connected to the opening 21 or tube 16,said vertical tube being provided at its lower end with a curved portion24 ending with a T portion 25 having an open vertical tube 26. Water canadvantageously flow within the tube 26 up to the curved portion 24, whenthe wave reaches a specific height. In this manner, the tube 26 willremain clean when the wave height is dropping. As the tube is wetted dueto the movement of water inside the caisson, dust particles will havethe tendency to adhere on the wetted surface when air is exhausted fromthe caisson, said dust particles being then removed when the wave heightin the caisson is dropping.

Said piping system is also advantageous as avoiding, in case ofexceptional wave height, a direct contact of water with the valve, andas acting as a means for limiting the passage of water vapour and/orwater droplets to the exhaust.

The opening 17 can be provided with a pivotable door 27, so as to enablethe passage of water from the pipe 15 towards the outside, but so as toprevent the passage of air from the room R into the pipe 15 through theopening 17.

The open and closed positions of the valve 10 are shown in FIGS. 3A and3B.

FIGS. 4A and 4B are views of a control valve mechanism comprising a pipe28 connecting the valve 10 with the caisson 2, said pipe 28 beingprovided at its end connected to the caisson, with a liquid blockingsystem 29 adapted to prevent the passage of liquid and gas towards thevalve 10, when the liquid level in the caisson is above a predeterminedlevel L1 (see FIG. 4B). This is also advantageous for ensuring a minimumair volume within the caisson. The anti blocking system 29 comprises forexample one or more floating elements, such as balls 30. The floatingballs are placed in a tube 28 provided at its bottom with arms 31 or agrid 32 for preventing the balls to fall outside the pipe 28, in casethe water level of the caisson is too low.

When the water level in the caisson reaches the level L1, the upper ball30A is pushed against the upper wall of the caisson provided with theopening 21. In said position the ball 30A closes at least partly theopening 21.

The blower is adapted to blow a volume of air of at least 30 litres persecond (for example comprised between 100 litres and 500 litres persecond) per 200 litres of the upper portion of the caisson.

The bottom of the caisson has an opening 5A having an open surfacecorresponding to 4% to 7% of the surface LS of the liquid of the pool.

FIG. 5A to 5C show different water level within the caisson 2.

In FIG. 5A, the water level L2 in the caisson is low, and extendsadvantageously lower than the water level L3 of the water outside thecaisson, but adjacent to said caisson. In FIG. 5A, the wave W in thepool adjacent to the caisson 2 is intended to further drop (arrow D).

The water level L2 within the caisson is advantageously in advance ofphase with respect to the wave phase.

In FIG. 5B, the water level L4 in the caisson 2 is high, but still lowerthan the maximum water level L5 outside the caisson 2, but adjacent tothe caisson.

In FIG. 5C, the water level L6 within the caisson 2 is lowered to belowthe level of the open bottom 5 of the caisson 2, whereby enabling toexpel possible materials attached to the grid 5B.

The controlled command system 14 comprises preferably instructions formaintaining the exhaust valve or valves of the caisson in its closedposition for a time sufficient so that a sufficient amount of air fromthe blower is introduced into the caisson, so that part of said air isexhausted into the pool through the bottom opening. This is advantageousfor expelling out of the caisson or out of the grid, possible materialsor components floating within the caisson or blocking partly the grid.Preferably, the instructions for maintaining the exhaust valve or valvesof the caisson in its substantially closed position for a timesufficient so that a sufficient amount of air from the blower isintroduced into the caisson are adapted for exhausting air into the poolfor at least 1 second to 10 minutes, preferably 5 second to 1 minute,per period of at least 45 minutes, advantageously per period comprisedbetween 1 hour and 24 hours.

This is advantageous for controlling the good working of the blower andof the exhaust valve(s) from time to time.

According to a specific embodiment, the caisson 2 has a lateral verticalwall 40 in contact with the liquid of the pool outside the caisson. Saidwall 40 has an opening 41 with a portion 41A at least located below theaverage liquid level ALS and a portion 41B located above the averageliquid level of the pool. Said opening 41 is provided with movableclosing means or door 42, for example vertically slidable. Said opening41 enables the passage of water from the pool into the caisson when theopening is not closed by the movable closing means.

In FIG. 6, the pool P is provided with two distinct caissons 2A,2Bconnected to a same air blower 6, through a piping system 8 providedwith a valving system 8A for controlling the flow of air towards thefirst caisson 2A and a valving system 8B for controlling the flow of airtowards the second caisson 2B.

Each caisson 2A,2B has at least one control valve mechanism connected tothe upper portion of the caisson. Said control valve mechanismcomprises:

-   -   an exhaust valve 9 adapted to move between at least a        substantially closed position and a substantially full open        position, and    -   a system 11 adapted to move the exhaust valve and to maintain        said exhaust valve into one position selected from the group        consisting of the substantially closed position, the        substantially full open position and partly open positions        comprised between the substantially closed position, the        substantially full open position.

The invention also relates to the use of the adaptive control artificialwave making device of the invention for generating artificial wave atthe surface of a pool, advantageously located in a room, preferably in asubstantially closed room. The air from the caisson is advantageouslyexhausted outside the room or towards a treatment station.

The artificial wave making device according to this invention mayeffectively generate continuous artificial wave suitable for aquaticbreeding, especially for prawn breeding to accelerate the growing rateof prawn (such as shrimp, crabs, lobsters, etc.) and to increase greatlythe output.

The artificial wave making device according to this invention is alsosuitable for aquarium, sport, recreation, such as for wave building in aswimming pool, and also for medical therapy such as water therapy. Theadaptive control artificial wave making device according to thisinvention has the advantages of a simplified structure, a reasonablecontrol system, a low energy consumption and wide application.

1. An adaptive control artificial wave making device for generating wavewith at least one specific wave pattern, at least at the surface of aliquid contained into a pool located in an air containing atmospherehaving an ambient pressure, said surface of the liquid having an averageliquid level, said wave making device comprising at least: a caissonadapted to be mounted at least partly into a pool containing a liquid,said caisson having at least one opening for the passage of liquid, atleast an upper portion and a bottom portion intended to be immersed inthe liquid of the pool below the average liquid level in the pool,wherein at least a part of the upper portion of the caisson is adaptedto contain air when the bottom portion of the caisson is immersed intothe liquid of the pool, and wherein said caisson having a face providedwith an opening adapted, when the caisson is partly immersed into theliquid, to form a passage of liquid from the pool towards the caisson,and inversely; an air blower adapted to create an outlet air flow withan air pressure at least equal to the atmospheric pressure; an air pipeconnecting the air blower to the upper portion of the caisson, so as tointroduce air into the upper portion of the caisson whereby generatingin said upper portion of the caisson an air pressure at least equal tothe atmospheric pressure; at least one control valve mechanism connectedto the upper portion of the caisson, said control valve mechanismcomprising at least one exhaust valve adapted to move between at least asubstantially closed position and a substantially full open position,and a system adapted to move at least one exhaust valve and to maintainsaid at least one exhaust valve into one position selected from thegroup consisting of the substantially closed position, the substantiallyfull open position and partly open positions comprised between thesubstantially closed position, the substantially full open position,whereby said control valve mechanism is adapted to ensure continuouslyair pressure within the caisson at least equal to the ambient pressure,at least one submersible pressure sensor placed at a determined levelfor determining a parameter selected from the group consisting of liquidpressure, a difference of pressure at a liquid level of the caisson, adifference of pressure vertically below the opening of the caisson,whereby at said determined level, liquid is always present when thecaisson is placed in the pool for generating wave, the said submersiblepressure sensor measuring a difference of pressure of the liquid at thedetermined level into the caisson with respect to the ambient pressureand generating an electrical signal, and a controlled command systemreceiving the electrical signal of the submersible pressure sensor, saidcontrolled command system (a) determining moments selected from thegroup consisting of the moments when at least one exhaust valve has tobe moved into a position selected from the group consisting of thesubstantially full open position and partly open positions comprisedbetween the substantially closed position, the moments when at least oneexhaust valve has to be moved into its substantially closed position,for achieving said specific wave pattern, and (b) emitting a signaltowards the control valve mechanism for commanding the movement of theexhaust valve for achieving said specific wave pattern at least at thesurface of the liquid contained into the pool.
 2. The adaptive controlartificial wave making device of claim 1, wherein the caisson has abottom face provided with an opening adapted, when the caisson is partlyimmersed into the liquid, to form a passage of liquid from the pooltowards the caisson, and inversely.
 3. The adaptive control artificialwave making device of claim 1, in which the air blower is adapted tocreate an outlet air flow with an air pressure with an over pressurecomprised between 0.05 10⁵ Pa and 0.3 10⁵ Pa above the atmosphericpressure, and so as to introduce air into the upper portion of thecaisson whereby generating in said upper portion of the caisson an airover pressure comprised between 0.01 10⁵ Pa and 0.3 10⁵ Pa above theatmospheric pressure.
 4. The adaptive control artificial wave makingdevice of claim 1, in which the submersible pressure sensor is placed inthe bottom portion of the caisson.
 5. The adaptive control artificialwave making device of claim 2, in which the submersible pressure sensoris located below the opening of the bottom face of the bottom portion ofthe caisson, at a determined level with respect to the bottom face ofthe caisson.
 6. The adaptive control artificial wave making device ofclaim 1, in which the submersible pressure sensor sends as signal, atleast an electrical signal function of the measured difference ofpressure, said electrical signal being of less than 100 mA.
 7. Theadaptive control artificial wave making device of claim 1, in which thecontrolled command system is associated to a converter for convertingthe electrical signal of the submersible pressure sensor into aconverted signal received by the controlled command system.
 8. Theadaptive control artificial wave making device of claim 1, in which thesystem adapted to move the exhaust valve and to maintain said exhaustvalve into one position selected from the group consisting of thesubstantially closed position, the substantially full open position andpartly open positions comprised between the substantially closedposition comprises at least one cylinder.
 9. The adaptive controlartificial wave making device of claim 1, in which the system adapted tomove the exhaust valve and to maintain said exhaust valve into oneposition selected from the group consisting of the substantially closedposition, the substantially full open position and partly open positionscomprised between the substantially closed position comprises at leastone cylinder, said cylinder acting against the action of a returnmechanism.
 10. The adaptive control artificial wave making device ofclaim 1, in which the system adapted to move the exhaust valve and tomaintain said exhaust valve into one position selected from the groupconsisting of the substantially closed position, the substantially fullopen position and partly open positions comprised between thesubstantially closed position comprises at least one cylinder, saidcylinder acting against the action of a return mechanism, said returnmechanism being adapted for directing the valve towards itssubstantially closed position.
 11. The adaptive control artificial wavemaking device of claim 9, in which the caisson is provided with anexhaust pipe for the exhaust of air from the caisson, whereby thecylinder is located within the exhaust pipe.
 12. The adaptive controlartificial wave making device of claim 1, in which the ratio opensurface of the exhaust valve or valves expressed in cm²/volume of theupper portion of the caisson is greater than 0.001.
 13. The adaptivecontrol artificial wave making device of claim 1, in which the ratioopen surface of the exhaust valve or valves expressed in cm²/volume ofthe upper portion of the caisson is comprised between 0.005 and 0.05.14. The adaptive control artificial wave making device of claim 1, inwhich the control valve mechanism comprises a pipe connecting theexhaust valve with the caisson, said pipe being provided at its endconnected to the caisson, with a liquid blocking system adapted toprevent the passage of liquid and gas towards the exhaust valve, whenthe liquid level in the caisson is above a predetermined level.
 15. Theadaptive control artificial wave making device of claim 1, in which thebottom of the caisson is open, said bottom being provided with a seriesof elements defining passages with a maximum width or diameter of lessthan 10 cm.
 16. The adaptive control artificial wave making device ofclaim 1, in which the blower is adapted to blow a volume of air of atleast 30 litres per second per 200 litres of the upper portion of thecaisson.
 17. The adaptive control artificial wave making device of claim1, in which the bottom of the caisson has an opening having an opensurface corresponding to 3% to 20% of the surface of the liquid of thepool.
 18. The adaptive control artificial wave making device of claim 1,in which the pool is located in a room, and in which the device comprisean exhaust pipe for exhausting air from the caisson outside the saidroom.
 19. The adaptive control artificial wave making device of claim 2,in which the controlled command system comprises instructions formaintaining the exhaust valve or valves of the caisson in itssubstantially closed position for a time sufficient so that a sufficientamount of air from the blower is introduced into the caisson, so thatpart of said air is exhausted into the pool through the bottom opening.20. The adaptive control artificial wave making device of claim 19, inwhich the instructions for maintaining the exhaust valve or valves ofthe caisson in its substantially closed position for a time sufficientso that a sufficient amount of air from the blower is introduced intothe caisson are adapted for exhausting air into the pool for 1 second to10 minutes per period of at least 45 minutes.
 21. The adaptive controlartificial wave making device of claim 1, wherein the caisson has abottom face provided with an opening adapted, when the caisson is partlyimmersed into the liquid, to form a passage of liquid from the pooltowards the caisson, and inversely, in which the controlled commandsystem comprises instructions for maintaining the exhaust valve orvalves of the caisson in its substantially closed position for a timesufficient so that a sufficient amount of air from the blower isintroduced into the caisson, so that part of said air is exhausted intothe pool through the bottom opening, and in which the instructions formaintaining the exhaust valve or valves of the caisson in itssubstantially closed position for a time sufficient so that a sufficientamount of air from the blower is introduced into the caisson are adaptedfor exhausting air for 5 seconds to 1 minute, per period comprisedbetween 1 hour and 24 hours.
 22. The adaptive control artificial wavemaking device of claim 1, in which the caisson has a lateral wall incontact with the liquid of the pool outside the caisson, the said wallhaving a set of at least two openings selected from the group consistingof a set comprising an opening with a portion at least located below theaverage liquid level and an opening with a portion located above theaverage liquid level of the pool, a set comprising at least a firstopening located above the average liquid level of the pool and a secondopening located below the average liquid level, and in which at leastone of said opening is provided with movable closing means, wherebyenabling the passage of water from the pool into the caisson when saidat least one opening is not closed by the movable closing means.
 23. Theadaptive control artificial wave making device of claim 1, whichcomprises at least one additional means selected from the groupconsisting of air filtering means, treatment units for filtering airflowing into the blower, treatment units for treating air flowing intothe blower, treatment units for filtering air pushed by the blower,treatment units for treating air pushed by the blower.
 24. The adaptivecontrol artificial wave making device of claim 1, which comprises atleast two distinct caissons connected to a same air blower through apiping system provided with a valving system for controlling the flow ofair towards the first caisson and the flow of air towards the secondcaisson, whereby each caisson has at least one control valve mechanismconnected to the upper portion of the caisson, said control valvemechanism comprising an exhaust valve adapted to move between at least asubstantially closed position and a substantially full open position,and a system adapted to move the exhaust valve and to maintain saidexhaust valve into one position selected from the group consisting ofthe substantially closed position, the substantially full open positionand partly open positions comprised between the substantially closedposition, the substantially full open position.
 25. A method forgenerating artificial wave at the surface of a liquid contained in apool located in a room, in which an adaptive control artificial wavemaking device of claim 1 is used, in which the air from the caisson isexhausted outside the room or towards a treatment station, said methodcomprising at least the following steps: creating by means of the airblower of an outlet air flow with an air pressure at least equal to theatmospheric pressure towards at least one caisson having its bottomportion immersed into the liquid, whereby generating in the upperportion of the caisson an air pressure at least equal to the atmosphericpressure; controlling by the working of at least one exhaust valveassociated to the upper portion of the caisson between at least asubstantially closed position and a substantially full open position, bythe system adapted to move said at least one exhaust valve and tomaintain said at least one exhaust valve into one position selected fromthe group consisting of the substantially closed position, thesubstantially full open position and partly open positions comprisedbetween the substantially closed position, the substantially full openposition, whereby said control valve mechanism is adapted to ensurecontinuously air pressure within the caisson at least equal to theambient pressure, whereby the pressure within the caisson varies so asto generate a liquid flow between the caisson and the pool; determininga parameter selected from the group consisting of liquid pressure, adifference of pressure at a liquid level of the caisson, a difference ofpressure vertically below the opening of the caisson, by at least onesubmersible pressure sensor placed at a determined level fordetermining, whereby at said determined level, liquid is always present,the said submersible pressure sensor measuring a difference of pressureof the liquid at the determined level into the caisson with respect tothe ambient pressure and generating an electrical signal, transmittingthe electrical signal to a controlled command system for (a) determiningmoments selected from the group consisting of the moments when at leastone exhaust valve has to be moved into a position selected from thegroup consisting of the substantially full open position and partly openpositions comprised between the substantially closed position, themoments when at least one exhaust valve has to be moved into itssubstantially closed position, for achieving said specific wave pattern,and (b) emitting a signal towards the control valve mechanism forcommanding the movement of the exhaust valve for achieving said specificwave pattern at least at the surface of the liquid contained into thepool.
 26. A method for generating artificial wave at the surface of aliquid contained in a pool located in a room, in which an adaptivecontrol artificial wave making device of claim 1 is used, in which theair from the caisson is exhausted outside the room or towards atreatment station, said method comprising at least the following steps:creating by means of the air blower of an outlet air flow with an airpressure at least equal to the atmospheric pressure towards at least onecaisson having its bottom portion immersed into the liquid, wherebygenerating in the upper portion of the caisson an air pressure at leastequal to the atmospheric pressure; controlling by the working of atleast one exhaust valve associated to the upper portion of the caissonbetween at least a substantially closed position and a substantiallyfull open position, by the system adapted to move said at least oneexhaust valve and to maintain said at least one exhaust valve into oneposition selected from the group consisting of the substantially closedposition, the substantially full open position and partly open positionscomprised between the substantially closed position, the substantiallyfull open position, whereby said control valve mechanism is adapted toensure continuously air pressure within the caisson at least equal tothe ambient pressure, whereby the pressure within the caisson varies soas to generate a liquid flow between the caisson and the pool;determining a parameter selected from the group consisting of liquidpressure, a difference of pressure at a liquid level of the caisson, adifference of pressure vertically below the opening of the caisson, byat least one submersible pressure sensor placed at a determined levelfor determining, whereby at said determined level, liquid is alwayspresent, the said submersible pressure sensor measuring a difference ofpressure of the liquid at the determined level into the caisson withrespect to the ambient pressure and generating an electrical signal,converting the electrical signal by a converter into a converted signal,transmitting the converted signal to a controlled command system for (a)determining moments selected from the group consisting of the momentswhen at least one exhaust valve has to be moved into a position selectedfrom the group consisting of the substantially full open position andpartly open positions comprised between the substantially closedposition, the moments when at least one exhaust valve has to be movedinto its substantially closed position, for achieving said specific wavepattern, and (b) emitting a signal towards the control valve mechanismfor commanding the movement of the exhaust valve for achieving saidspecific wave pattern at least at the surface of the liquid containedinto the pool.